Q: Is 1,661,604 a Prime Number?
A: No, 1,661,604 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1661604 can be evenly divided by 1 2 3 4 6 7 12 14 21 28 42 84 131 151 262 302 393 453 524 604 786 906 917 1,057 1,572 1,812 1,834 2,114 2,751 3,171 3,668 4,228 5,502 6,342 11,004 12,684 19,781 39,562 59,343 79,124 118,686 138,467 237,372 276,934 415,401 553,868 830,802 and 1,661,604, with no remainder.
Since 1,661,604 cannot be divided by just 1 and 1,661,604, it is not a prime number.